1. Field of the Invention
The present invention relates to a controller of a tuner apparatus, and, in particular, to a controller of a tuner apparatus which contains a tuner, such as a liquid-crystal-display television set, a notebook-type personal computer, or the like.
The present invention also relates to a method for controlling power supply to such a tuner of such a tuner apparatus.
Recently, a television set, which is driven by power supplied by a battery, such as a liquid-crystal-display television set, and a notebook-type personal computer which is driven by power supplied by a battery and displays a television picture on a liquid crystal display, which is contained in the television set, have been developed. Such an apparatus is driven by a battery and a driving time period (a time period during which the apparatus can be driven by power supplied by a battery) thereof is limited. Accordingly, it is demanded to reduce power consumption in such an apparatus so as to elongate the driving time period of the apparatus.
2. Description of the Related Art
An apparatus which contains a television tuner and in which power consumption is reduced is disclosed in Japanese Laid-Open Patent Application No. 61-273074 or Japanese Laid-Open Patent Application No. 5-236394.
In Japanese Laid-Open Patent Application No. 61-273074, a magnetic picture-recording-and-reproducing apparatus with a television set is disclosed, which includes a television tuner portion for receiving a television broadcast, a VTR portion for recording a video signal and reproducing a picture, a television monitor portion for displaying a picture, a power supply portion for supplying power to the respective portions via a main switch, and a sub-switch for stopping power supply to the television tuner portion in a reproduction mode, and in which apparatus power consumption is effectively reduced.
Further, in Japanese Laid-Open Patent Application No. 5-236394, a television set is disclosed, which includes an external input terminal through which a video signal is input externally, a tuner circuit, an input switching circuit for switching a video signal between a video signal input through the external input terminal and the video signal input from the tuner circuit, a video-signal processing circuit, a picture tube for displaying a picture signal, a video-signal presence/absence detecting circuit for detecting presence and absence of a video signal, and a control circuit for turning off a power supply circuit for supplying power to a picture-tube body when absence of the video input signal is detected, which apparatus prevents turning off of power supply from being forgotten.
However, In the magnetic picture-recording-and-reproducing apparatus with a television set disclosed in Japanese Laid-Open Patent Application No. 61-273074, in a mode other than the reproduction mode of the VTR portion, power is supplied to the television tuner portion, even in a condition where an antenna is not connected with the television tuner portion or in a condition where the antenna is connected with the television tuner and only a faint signal is received. As a result, although it is not possible to substantially watch a television picture, a meaningless picture is displayed, and power is consumed wastefully in the television tuner portion.
In the television set disclosed in Japanese Laid-Open Patent Application No. 5-236394, as mentioned above, the power supply circuit for the picture tube body is turned off when absence of the video signal is detected. However, even in a condition where an antenna is not connected with the tuner circuit or in a condition where the antenna is connected with the tuner circuit and only a faint signal is received, absence of the video signal is not detected in the video-signal presence/absence detecting circuit because a faint video signal component is input. As a result, the power supply circuit for the picture tube body is not turned off, and power is wastefully consumed.
The present invention has been devised in consideration of the above-mentioned problems, and an object of the present invention is to provide a tuner apparatus and a method for controlling power supply to a tuner of such a tuner apparatus, in which a power supply to a television tuner is stopped either in a condition where an antenna is not connected with a tuner circuit or in a condition where the antenna is connected with the tuner circuit and only a faint signal is received, wasteful power consumption is eliminated, and thus, a driving time period of the apparatus can be elongated.
A tuner apparatus, according to the present invention, containing a tuner, comprises:
signal reception determining means for determining, in accordance with a signal supplied by the tuner and indicating a signal reception condition, whether or not signal reception has been performed normally; and
power supply stopping means for stopping power supply to the tuner when the signal determining means determines that signal reception has not been performed normally.
Thus, it is determined, in accordance with the signal supplied by the tuner and indicating the signal reception condition, whether or not signal reception has been performed normally, and power supply to the tuner is stopped when it is determined that signal reception has not been performed normally. As a result, it can be prevented that a meaningless picture is displayed and power is consumed wastefully.
The tuner apparatus may further comprise antenna connection detecting means for detecting whether or not an antenna has been connected to the tuner apparatus,
wherein the power supply stopping means stops power supply to the tuner when the antenna connection detecting means determines that the antenna has not been connected to the tuner apparatus.
Thus, it is determined, in accordance with the signal supplied by the tuner and indicating the signal reception condition, whether or not signal reception has been performed normally, and power supply to the tuner is stopped when it is determined that signal reception has not been performed normally. Further, it is detected whether or not the antenna has been connected to the tuner apparatus, and power supply to the tuner is stopped when it is determined that the antenna has not been connected to the tuner apparatus. As a result, it can be prevented that a meaningless picture is displayed and power is consumed wastefully.
A tuner apparatus, according to another aspect of the present invention, containing a tuner, comprises:
antenna connection detecting means for detecting whether or not an antenna has been connected to the tuner apparatus; and
power supply stopping means for stopping power supply to the tuner when the antenna connection detecting means determines that the antenna has not been connected to the tuner apparatus.
Thus, it is detected whether or not the antenna has been connected to the tuner apparatus, and power supply to the tuner is stopped when it is determined that the antenna has not been connected to the tuner apparatus. As a result, it can be prevented that a meaningless picture is displayed and power is consumed wastefully.
The power supply may comprise power supply by a battery.
Thus, it is determined, in accordance with the signal supplied by the tuner and indicating the signal reception condition, whether or not signal reception has been performed normally, and power supply to the tuner is stopped when it is determined that signal reception has not been performed normally. Further, it is detected whether or not the antenna has been connected to the tuner apparatus, and power supply to the tuner is stopped when it is determined that the antenna has not been connected to the tuner apparatus. As a result, it can be prevented that a meaningless picture is displayed and power is consumed wastefully. Thereby, it is possible to elongate the life of the battery.
The tuner apparatus may comprise a notebook-type personal computer.
In this notebook-type personal computer, wasteful power consumption can be prevented, and the life of the battery can be elongated.
The signal supplied by the tuner and indicating the signal reception condition may comprise an automatic fine tuning signal which shows an S-curve characteristic.
Thereby, it is possible to effectively determine whether or not the normal signal reception has been performed.
The antenna connection detecting means may detect whether or not the antenna has been connected to the tuner apparatus, as a result of detecting whether or not a plug of the antenna has been loaded into a jack of the tuner apparatus.